Equine Lice

Lice infection, scientifically called pediculosis, can be introduced to a farm through infested equipment. Lice are host specific; therefore, equine lice do not affect other animals. Most lice species only live for a short time off the host.

  1. Contributing Factors

    • Long winter coats and infrequent grooming contribute to favorable conditions for lice to breed. According to Bill Clymer, livestock parasitologist, it is also believed that horses who are stressed by inadequate diet, illness, injury, or severe winters are more susceptible to lice.

    Symptoms

    • Symptoms of heavy infestations include anemia, deteriorating condition, stunted growth in young horses, uneasiness, alopecia loss of hair and sores from rubbing.

    Sucking Lice

    • The more common of two types of lice are sucking lice. They have piercing mouth parts which make them more harmful than chewing lice since they feed on the horse's blood. The lice lay eggs which attach to the horse's hair. Their complete life cycle is two to four weeks.

    Chewing Lice

    • The chewing lice feed only on skin scales. There are two species of chewing lice: Bovicola equi and Trichodectes pilosus. These lice are typically found on the head, mane, tail base and shoulder area.

    Treatments

    • Lice are extremely contagious so infected horses should be quarantined. Treatment choices include dusting powders, ivermectin wormers and insecticidal shampoos. Treat blankets and tack at the same time, and keep all horses out of infected pastures and round-pens for 14 days to starve any active lice.